Various types of mobile devices are known in the prior art. However, what has been needed is a mobile device with an expandable display screen including a first housing having a first display screen, a first camera, a rechargeable battery, a speaker, a microphone, a plurality of controls, a rearwardly extending L-shaped first tab, and a rightwardly extending L-shaped second tab. What has been further needed is a second housing slidably attached to the first housing, with the second housing having a second display screen, an audio port, a second camera, a charging port, a leftwardly extending L-shaped third tab, and a frontwardly extending L-shaped fourth tab. Lastly, what has been needed is for the second housing to have an extended position and an alternate retracted position. The second housing is in the extended position when the first housing is collinearly disposed adjacent to the second housing. The second housing is in the retracted position when the second housing is disposed directly behind and parallel to the first housing. The second tab is selectively lockable adjacent to the third tab when the second housing is in the extended position, and the third tab and the fourth tab are selectively lockable adjacent to the first tab and the second tab, respectively, when the second housing is in the retracted position. The mobile device with an expandable display screen, which is optionally shatterproof and waterproof, thus provides a user of the device with the option to temporarily double the size of a display screen while retaining the features and capabilities of the mobile device.